JPH0458958A - Blood pump - Google Patents

Abstract

PURPOSE: To provide a continuous blood flow and accurately measure the flow by providing a means for enhancing the pressure of the blood in a pump main body, providing a means for easing the blood pulsation which flows out from the pump main body, and incorporating a film which covers over an closes a housing and its cumulative material in the pulsation easing means. CONSTITUTION: A pump P is provided with a pressure raising means M and, when a drive motor 12 is operated, a plunger 10 vibratingly reciprocates. A main body B is provided with a cumulative cavity, namely, a cumulative chamber 16 and a pulsation easing means D composed of a flexible film 18. The plunger 10 reciprocates in a pressurization chamber 20. This constitution fills the pressurization chamber 20 with the blood and lets it flow to an outlet port 26. The flexible film 18 moves by the pressure of the blood flow flowing to the outlet port 26. As a result, the liquid in the cumulative chamber 16 is contacted so as to communicate the flow between the outlet port 26 and an outlet chamber 28. On the contrary, when the pump is in an intake stroke and a valve 24 is closed, the flexible film 18 covers across the outlet chamber 28 and the outlet port 26 completely so as to prevent any flow.

Description

TECHNICAL FIELD The present invention relates to the field of blood pressure elevation devices for use during surgery or coronary angioplasty.

BACKGROUND OF THE INVENTION In recent years, balloon angioplasty has become increasingly popular as a means of treating patients with arterial stenosis. Furthermore, it has been desired to provide a catheter that has a minimal external shape and can be inserted into the most constricted area of a blood vessel. Additionally, it is desirable to continue blood flow during balloon inflation to avoid local anemia that is likely to occur when the balloon deflates.

Reducing the catheter profile has resulted in a progressively smaller catheter lumen that transports blood through the balloon distended end. As a result, increasingly higher pressures were required to force the required amount of blood through the reduced cross-sectional area of the catheter lumen.

The concept of incorporating a pump to pump balloon-inflated bovine blood was first published in U.S. Patent Application No. 1 filed on September 23, 1987.
It was first described in No. 00,363.

In the past, peristaltic pumps were used to pump blood. However, such pumps have two drawbacks. First, there is a limitation in the ability to generate output pressure.

In contrast, the pump of the present invention can generate pressures up to about 300 psig. Second, the tubing used in peristaltic pumps can undergo partial collapse, and the resulting particles enter the blood stream with undesirable consequences.

Not only is it important to pump a specific amount per unit time into the catheter during coronary angioplasty;
It is also important to be able to know the pressure produced by the pump, which can be used as a factor in determining blood flow.

Typically, positive displacement pumps, such as piston type pumps, produce a pressure pulse with each stroke.

The device of the present invention provides such a pump with a pulsation mitigation mechanism to smooth pressure pulses, thereby providing a continuous flow of blood during balloon inflation and enabling accurate flow rate measurement. The main body of the pump, including the pulsation dampening mechanism, can be made from disposable materials. This pump body can be used in combination with a reusable electric motor and drive. The pump body of the present invention can also be operated in any position and is small enough to be used to pump blood to a patient's heart in emergency situations, such as emergency bypass surgery.

Pulsation dampeners have been used in multi-cylinder piston pumps in oil and gas wells as a means to reduce vibration of the vibrator at the pump discharge end when pumping various well fluids.

Piston-type pumps have been used to pump saline and other medications into intravenous catheters.

Peristaltic pumps have been used to fill coronary arteries with blood during heart surgery. This peristaltic pump is a very low pressure pump, up to 80-120 psig. In addition, peristaltic pumps are slippery pumps and cannot provide a quantitatively reliable flow. With the advent of smaller diameter angioplasty catheters, there has been a need to generate higher blood pressures so that sufficient blood can be pumped into the smaller diameter catheters during PTCA. be. The pump of the present invention meets this requirement.

SUMMARY OF THE INVENTION The present invention is a disposable positive displacement piston pump having a polycarbonate body, piston, mouth valve, and outlet valve. The outlet valve is connected to an outlet chamber which is separated from the outlet valve by an elastomeric membrane. An elastomeric membrane surrounds the storage chamber, which is filled with a fluid such as air at atmospheric pressure. The pulsations in the outlet pressure caused by the reciprocating movement of the piston cause the elas I
・It is relieved by the deflection effect performed by the membrane while compressing the fluid in the storage chamber. The output of the pump is depressurized to provide sufficient pressure to force blood through a minimal cross-sectional angioplasty catheter having a through-filling lumen. The combination of this pump and a minimal cross-sectional balloon angioplasty catheter, along with the ability to pump a sufficient amount of blood through such a minimal cross-sectional catheter during balloon inflation while substantially eliminating pressure pulsations on each stroke; This allows the catheter to be passed through narrowed passages.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, pump P includes a body B. As shown in FIG. The pump P also has a booster means M including a plunger 10, a drive motor 12 and a linkage 14. Activation of the drive motor 12 causes an oscillatory reciprocating motion of the plunger 10.

As is clear from FIG. 1, the body B includes pulsation dampening means. The pulsation dampening means includes a storage cavity or storage chamber 16 and preferably has a Shore hardness of 60A to 55D.
A flexible membrane 18 made of polyurethane is included. Although FIG. 1 shows the pulsation mitigation means integrated with the body B, the pulsation mitigation means may be separable from the body B without departing from the invention.

Pump P also includes a pressurized chamber 20 . Plunger 10
moves reciprocally within this pressurizing chamber 20. Inlet valve 22 and outlet valve 24 are in fluid communication with pressurized chamber 20 .

When plunger 10 moves in a direction that expands the volume of pressurized chamber 20, this movement opens valve 22 and closes valve 24. This fills the pressurizing chamber 20 with blood. Conversely, when plunger 10 moves in the opposite direction, valve 22 is biased to its closed position and valve 24 is opened. Blood therefore flows through valve 24 to outlet port 26. This flow of blood into the outlet port creates pressure therein which causes the flexible membrane 18 to move. This compresses the fluid within storage chamber 16 and establishes flow communication between outlet port 26 and outlet chamber 28. The storage chamber 16 can be filled with air at atmospheric pressure. It is not outside the scope of this invention to use other fluids and/or initial chamber pressures higher than atmospheric pressure. Conversely, when the pump is on the intake stroke and valve 24 is closed, flexible membrane 18 completely covers outlet chamber 28 and outlet port 26, preventing flow between these areas. This is because the flexible membrane 18 is seated on the wall 30.

After the blood has passed into the outlet chamber 28, it exits to the outlet opening 32. An inlet tube 34 is connected to the inlet port 36 and an outlet tube 38 is connected to the outlet opening 32.

A suitable material for body B is polycarbonate, but
Other materials may also be used without departing from the spirit of the invention. This material of body B is preferably transparent, so that air bubbles, if present, can be easily detected in the blood.

Furthermore, the transparent body B makes it possible to immediately check the condition of the flexible membrane 18.

The drive mechanism 14 is preferably of the reversible pole screw type. However, other types of vibratory motion may be used without departing from the spirit of the invention.

As shown in FIG. 2, outlet tube 38 is connected to a fitting 40 of vascular style catheter A. As shown in FIG. This angioplasty catheter A has a lumen 42 and a balloon 44 extending therethrough. The balloon 44 blocks blood flow within the artery 46 when inflated as shown in FIG. When the pump P is activated, blood is withdrawn directly or indirectly from a blood source, such as a blood bag, or from the patient himself, such as from a renal vein or artery. This blood passes from the inlet tube 34 via the pump to the outlet tube 38 and exits through the lumen 42 of the angioplasty catheter A at its distal end 48. Operation of the pump causes blood 50 to pass through end 48 of angioplasty catheter A.

Therefore, since the blood 50 is flowing within the artery 46 while the balloon 44 is inflated, there is no fear of local anemia due to contraction of the blood vessel. The use of pump P makes it possible to increase the blood pressure, thus making it possible to have a small cross-sectional size angioplasty catheter A with a smaller diameter lumen 42 and to pump a sufficient volume through this angioplasty catheter. Allows blood to be sent.

The pump P of the present invention is of a portable type and can be operated in any position. This pump is about 1-17
It is small, measuring 2' x 41/2' x 3 1/2'. The drive is approximately 4' x 3'XIO' in size. A structure combining these is lightweight and easy to carry.

After use, the pump section is discarded and the drive motor and linkages 12 and 14 are reused in another sterile pump.

The addition of the storage chamber 16 to the flexible membrane 18 further smoothes the blood pressure pulse, allowing for more accurate blood flow and blood pressure measurements. This measurement can be performed by attaching a suitable device to the outlet tube 38 or between the outlet tube 38 and the fitting 40.

Alternatively, chamber 20 and plunger 10 may be of double action construction, not shown. In this manner, blood is pumped out regardless of the manner in which the plunger 10 reciprocates. This structure reduces pulsations and can be used with or without pulsation mitigation means.

Although the present invention has been described in detail with respect to the preferred embodiment thereof illustrated in the accompanying drawings, the present invention is not limited to this specific embodiment, and many changes and modifications may be made without departing from the spirit of the invention. Of course it can be done.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a blood pump according to the invention, and FIG. 2 is a schematic diagram showing a combination of the blood pump and angioplasty balloon catheter shown in FIG. 10...Plunger, 12...Drive motor, 14...Linkage, 16...Storage chamber, 18...Flexible membrane, A
...Angioplasty catheter, B.. Main body, D.. Pulsation mitigation means, P.. Pump, 20.. Pressurization chamber, 22.. Inlet valve, 24.. Outlet valve, 26.. Outlet port, 28.・Outlet chamber, 30... Wall, 32... 1 outlet, 34... Inlet pipe, 36... Inlet port, 38... Outlet pipe, 40... Fixture, 42... Inner cavity, 44... Balloon, 46... artery.

Claims (1)

[Scope of Claims] 1. A pump body, means provided in the pump body to increase the pressure of blood passing therethrough, and means in flow communication with the pump body to dampen the pulsation of blood exiting the pump body. A blood pump comprising: a blood pump characterized in that the means for damping blood pulsation includes a housing defining an accumulation chamber and a membrane covering and closing the accumulation chamber. 2. The blood pump according to claim 1, wherein the pulsation mitigation means is integral with the pump body, and the membrane prevents the formation of dead spots where blood accumulates in the flow path within the pump body. A blood pump characterized in that the blood pump is disposed within the blood pump. 3. The blood pump of claim 1, wherein the blood pressure increasing means includes at least one inlet valve, at least one outlet valve, and at least one defining a volume in fluid communication with both the inlet valve and the outlet valve. a pressurized chamber,
A blood pump characterized in that it includes means for changing the volume of the pressurizing chamber. 4. The blood pump according to claim 3, wherein the pressurized chamber has a cylindrical shape, and the means for changing the volume is a piston. 5. The blood pump of claim 3, wherein the outlet valve is in flow communication with an outlet port of the body, the membrane covers the outlet port when the outlet valve is in the closed position, and the accumulation chamber is in flow communication with the outlet port of the body. the body further includes an outlet chamber remote from the outlet port, the outlet valve being opened and the membrane deflecting to reduce the volume of the accumulation chamber; A blood pump characterized in that an outlet chamber is in flow communication with the outlet port. 6. The blood pump of claim 5, wherein the body further includes an outlet opening in flow communication with the outlet chamber. 7. The blood pump of claim 6 including a balloon angioplasty catheter having a filled lumen with an inner diameter of approximately 0.020 inch extending adjacent to and extending through the distal end; A blood pump having flow communication with a filled lumen of said catheter to thereby reduce pulsation and allow pressurized blood to be pumped through the catheter during a balloon angioplasty procedure. 8. The blood pump of claim 1, comprising a balloon angioplasty catheter having a filled lumen having an inner diameter of approximately 0.020 inches adjacent to and extending through the distal end; in flow communication with the filled lumen of the blood pump for pumping pulsation-relieving pressurized blood through the catheter during a balloon angioplasty procedure. 9. A blood pump according to claim 7, wherein the pulsation mitigation means is integral with the body, and the membrane is disposed within the pulsation mitigation means to avoid the creation of dead spots where blood accumulates in the flow path in the body. A blood pump characterized in that: 10 a body defining a cavity therein, at least one double-acting piston dividing the cavity into at least one first and second chamber, and an inlet in flow communication with the first and second chambers; and an outlet valve to assist in pressurizing the blood in the first chamber as the piston moves in one direction and to assist in pressurizing the blood in the second chamber as the piston moves in the opposite direction. The blood pump is characterized in that the two valves are selectively activated in response to movement of the piston to permit sequential activation of the two valves. 11. The blood pump according to claim 10, further comprising means provided in the main body for alleviating pressure pulsations of blood as it exits the pump, the pulsation alleviating means further defining an accumulation chamber therein. A blood pump characterized in that it includes a housing and a membrane that covers and closes this storage chamber. 12 includes a blood pump capable of producing a pressure of at least 120 psig and means in flow communication with the blood pump to dampen the pulsation of blood as it exits the blood pump, the pulsation dampening means being capable of producing a pressure of at least 120 psig; a housing defining an accumulation chamber; a membrane overlying and closing the accumulation chamber; and a fill lumen having an inner diameter of approximately 0.020 inches extending therethrough adjacent to the distal end. an angioplasty catheter with an angioplasty catheter, the blood pump being in flow communication with the filling lumen such that blood is pumped from the lumen and the distal end of the catheter when the catheter is used on a patient. characterized by
A device that fills blood during angioplasty. 13. The apparatus of claim 8, wherein the pressure increasing means further includes an inlet port adapted to be mounted to a renal vein or artery of the patient, thereby providing continuous flow of blood through the pump and the catheter during an angioplasty procedure. A device characterized in that it allows a target to flow. 14. The apparatus of claim 12, wherein the pump further includes an inlet port adapted to be mounted to a renal vein or artery of the patient, thereby continuously directing blood through the pump and the catheter during an angioplasty procedure. A device characterized in that it allows water to flow through the air. 15. The apparatus of claim 1, wherein said pressure raising means is capable of generating a pressure of at least about 120 psig. 16. The apparatus of claim 7, wherein said pressure raising means is capable of producing a pressure of at least about 120 psig. 17. The apparatus of claim 10, wherein the pump is capable of producing a pressure of at least about 120 psig. 18. The apparatus according to claim 1, wherein the pump further includes drive means connected to the pressure increasing means for selectively operating the pressure increase means, and the pump including the drive means is portable. A device that does this. 19. The apparatus according to claim 7, wherein the pump further includes drive means connected to the pressure increase means for selectively operating the pressure increase means, and the pump including the drive means is portable. A device that does this. 20. The apparatus according to claim 10, wherein the pump further includes drive means connected to the piston for selectively driving the piston, and the pump including the drive means is portable. Device. 21. The apparatus according to claim 12, wherein the pump further includes drive means connected to the piston for selectively driving the piston, and the pump including the drive means is portable. Device. 22. The device according to claim 18, wherein the main body, pressure increase means and pulsation mitigation means are disposable;
Apparatus characterized in that the drive means is reusable with a replacement unit comprising the main body, pressure increase means and pulsation mitigation means. 23. The device according to claim 19, wherein the main body, the pressure increase means and the pulsation mitigation means are disposable;
Apparatus characterized in that the drive means is reusable with a replacement unit comprising the main body, pressure increase means and pulsation mitigation means. 24. The device of claim 20, wherein the body is disposable and the drive means can be used with a replaceable body. 25. A device according to claim 21, characterized in that the body is disposable and the drive means can be used with a replaceable body. 26. The blood pump of claim 11, wherein the pulsation mitigation means is integral with the body, and the membrane reduces the pulsation in a manner that avoids the creation of dead spots where blood accumulates within the flow path in the body. A blood pump, characterized in that it is disposed within a means. 27. The blood pump of claim 12, wherein the pulsation mitigation means is integral with the body, and the membrane reduces the pulsation in a manner that avoids the creation of dead spots where blood accumulates within the flow path in the body. A blood pump, characterized in that it is disposed within a means.